Ore-roasting furnace.



No. 664,l53. Patented Dec. I8, |900. F. W. HULTMAN.

ORE RUASTING FURNACE.

(Application Xed Aug. 20, 1900.) (No Modal.) 2 Shania-Sheet l.

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I I Y 'Adolf/ley No. s64,|53. i Patented nec. la, |900. F. w. HoLTMAN.

'URE RUSTING FURNACE.

(Application led. Aug. 20, 1900.)

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FREDERICK W. HOLTMAN, 0F RICHMOND, VIRGINIA.

GRE-ROASTING FU RNACE.

SPECIFICATION forming` part of Letters Patent No. 664,153, datedDecember 18, 1900.

Application filed August 20,1900. Serial No. 27,458. (No model.)

.To all whom it may concern:

Be it known that I, FREDERICK W. HoL'r- MAN, a citizen of the UnitedStates, residing at Richmond, in the county of Henrico and State ofVirginia, have invented certain new and useful Improvements inOre-Roasting Furnaces; and I do declare the following to be afullf,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, and to theletters of reference marked thereon,which form apart of thisspecification.

This invention relates to new and useful improvements in ore-roastingfurnaces, and especially to furnaces in which reciprocating rake-teethare utilized to stir and feed the ore from one bed to another, saidteeth being operated by means of threaded shafts mounted outside thefurnace-walls and on which shafts interiorly-threaded nuts are mountedto travel, which nuts are fastened to the racks carrying the teeth,whereby the teeth may be reciprocated backward and forward upon thebeds.

My invention will be hereinafter more fully described and thenspecifically defined in the appended claims, and is illustrated in theaccompanying drawings, which, with the letters of reference markedthereon, form a part of y this application, and in which drawingssimilar letters of reference indicate like parts throughout the severalviews, in which- Figure lis a side elevation of an ore-roasting furnace,showing the slot-covering plates projecting beyond the end of thefurnace. Fig. 2 is an end elevation of the furnace, a portion of thewall being broken away to better illustrate a section of one of therake-carrying racks and a portion of one of the beds. Fig. 3 is a topplan view of one of the racks which carries the rake-teeth, said viewshowing the sleeves for holding the ends of the racks and the threadedshafts and interiorlythreaded nuts which travel on said threaded shafts.Fig. 4 is a bottom plan view of the rack, showing thetriangular-outlined teeth carried thereby.

Reference now being had to the details of the drawings by letter, Adesignates the wall of the furnace, made, preferably, of heavy ironplate or castings filled in with {ire-brick,

as is the common construction of furnaces of this character. Within thefurnace are parallel beds B of tiling, which extend from one side wallto the other across the furnace. These beds are disposed parallel withone another, there being four shown in the drawings, Fig. 2. These bedshave the alternatelyarranged outlet-apertures near the ends of the beds,which are common in furnaces of this character and through which the oreis allowed to fall by gravity from one bed to another by means of therake-teeth as they are reciprocated back and forth on the upper surfacesof the beds.

The feeding-hopper C is mounted on one end of the furnace andcommunicates with the space above the upper of said beds B, and theregulation of the feeding of the ore is done by means of a rotary drumC', which is common in the art. Therefore a detailed description of itsconstruction and operation, it is thought, is not necessary. Suffice itto say that the drum is operated by belted connection D with a pulley E,which is mounted upon and driven by the shaft F, which latter isoperated from any source of power.

The sides of the furnace are slotted, as shown at G, each slot being aslight distance above a bed B and extending the length of the interiormeasurement of the furnace. These slots are in the opposite longitudinalwalls of the furnace, and sleeves H, Figs. 2 and 3, work backward andforward in these slots. To the inner ends of said sleevesY are held theends of the racks J, to which are fastened the rake-teeth I, which arepreferably triangular-shaped in cross-section. To the outer ends of saidsleeves are bolted or otherwise fastened the interiorly-threaded nuts K,which embrace the threads of the shaft L and travel thereon. Said shaftsL, which are eX- teriorly threaded., are mounted in suitable bearings onthe outside of the furnace, and each shaft L is parallel with said slotsand adjacent thereto. Bevel gear wheels M are keyed to the forward endsof the shafts L and mesh with bevel gear-wheels N, which are mountedupon and rotate with the vertical shafts O, one on either side of thefurnace outside the wall thereof. At the lower ends of said verticalshafts O are the bevel gear- IOO wheels O', which mesh with gear-wheelsP, that are keyed to the horizontal shaft F.- This shaft F may be drivenfrom any source of supply whereby a certain number of revolutions may beimparted to said shaft and then the shaft made to rotate in the oppositedirection for the purpose of reciprocating the racks carrying therake-teeth through the geared connections described. As no novelty isclaimed for the reversing mechanism in connection with shaft F, saidmechanism is not illustrated.

Connected to each sleeve H, on opposite edges thereof, are theslot-covering plates R, which plates are shown in Fig. 1 as projectingbeyond the end wall of the furnace, which are the positions that saidplates would assume when the racks carrying the rake-teeth are at theforward end of the furnace. When the rakes are at their farthestbackward throw, the plates, which are secured to the opposite edges ofthe sleeves, would project correspondingly beyond the rear wall of thefurnace. By the provision of these plates it will be observed that theslots are kept closed while the sleeves carrying the racks with therake-teeth reciprocate backward and forward in said slots.

By the provision of the split nuts,whicl1 are interiorly threaded, thenuts may be easily removed and adjusted, and by having the ends of theracks J seated in the inner ends of the sleeves H the racks are allowedto eX- pand and contract freely.

The operation of the rakes is similar to the reciprocating movements ofrakes in this type of furnace, the ore being rst turned by means of theangled surfaces of the teeth and then pushed forward by the flat facesof the teeth, which flat faces are presented at right angles to theslotted walls of the furnace in a manner as is shown in the constructionof the well-known Spence patent, No. 248,521, of October 18, 1881.

By means of the threaded shafts on which the interiorly-threaded nutstravel the racks are reciprocated backward and forward, the rake-teethfeeding the ore from one bed to another, as will be readily understood.

Having thus described my invention, what I claim to be new, and desireto secure by Letters Patent, is-

1. An ore-roasting furnace, having a vertical series of beds therein,the walls of said furnace being slotted horizontally adjacent to theupper surfaces of said beds, sleeves and rack-bars supported thereby,rake-teeth carried by said bars, interiorly-threaded nuts havingintegral shank portions which are connectod to said sleeves, anddesigned to travel in said slots, worm-shafts working through said nuts,shutters fastened to the opposite edges of the shank portions of thenuts vand designed to close said slots and slide against the outer wallsof the furnace, as the racks are reciprocated over the beds and meansfor rotating the worm-shaft, as set forth.

2. In combination in an ore-roasting furnace, the beds, the racks havingrake-teeth s eoured thereto, the sleeves having recessed ends designedto receive the ends of said racks, the outer ends of said sleeves beingcontracted with inclined edges, theinteriorlythreaded nuts havingintegral shank portions which are fastened to the contracted ends of thesleeves, the threaded shafts'working through said nuts, and means foroperating said shafts, as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

FREDERICK W. HOLTMAN.

Vitnesses:

T. H. WEIMER, W. H. CHILDRESS.

